1 Scope
This part of ISO 5167 specifies the geometry and method of use (installation and operating conditions)
of wedge meters when they are inserted in a conduit running full to determine the
flow rate of the fluid flowing in the conduit.
As the uncertainty of an uncalibrated wedge meter can be too large for a particular
application, it might be deemed essential to calibrate the flow meter in accordance
with Clause 7 of this document. This part of ISO 5167 includes requirements for calibration which, if applied, are for use over the calibrated
Reynolds number range. Clause 7 might also be useful guidance for calibration of meters of similar design but which
fall outside the scope of this document.
This part of ISO 5167 also provides background information for calculating the flow rate and is applicable
in conjunction with the requirements given in ISO 5167‑1.
This part of ISO 5167 is applicable only to wedge meters in which the flow remains subsonic throughout
the measuring section and where the fluid can be considered as single-phase. Uncalibrated
wedge meters can only be used within specified limits of pipe size, roughness, beta
(or wedge ratio ) and Reynolds number. This part of ISO 5167 is not applicable to the measurement of pulsating flow. It does not cover the use
of uncalibrated wedge meters in pipes sized less than 50 mm or more than 600 mm, or
where the pipe Reynolds numbers are below 1 × 10 4 .
A wedge meter has a primary element which consists of a wedge-shaped restriction of
a specific geometry. Alternative designs of wedge meters are available; however, at
the time of writin...
Open preview (PDF)Measurement of fluid flow by means of pressure differential devices inserted in circular cross-section conduits running full - Wedge meters